Radio communication apparatus

1. A radio communication apparatus configured to read and write data from and to transponders, the radio communication apparatus comprising: a memory unit which stores data to be written to the transponders; a reading unit which, in response to a write command instructing that write data stored in the memory unit should be written to one of the transponders during a data-writing process, performs radio communication with the one of the transponders prior to the data-writing process, wherein the radio communication includes reading data stored in the one of the transponders in a non-contact fashion; a collating unit which, prior to the data-writing process, collates the data read from the one of the transponders by the reading unit with the write data, wherein the collating unit compares a first group of words in the write data to respective words in the read data, and compares a second group of words in the write data to respective words in the read data; and a control unit which performs radio communication with the one of the transponders, thereby writing the write data to the transponder when the collated data are not identical, and skipping the writing of the write data when the collated data are identical, wherein the control unit skips writing the first group of words to the one of the transponders when the first group of words matches the respective words in the read data, writes the second group of words to the one of the transponders when the second group of words does not match the respective words in the read data, receives a response signal from the one of the transponders after writing the write data to the one of the transponders, and determines whether there is an error in the one of the transponders based on the response signal, and wherein the write data is written to the one of the transponders, in units of words each consisting of a plurality of bytes; the collating unit collates the write data and the data read from the transponder by the reading unit, word by word; and the control unit determines whether the writing of the write data should be skipped, for each word.

2. The radio communication apparatus according to claim 1 , wherein the control unit acquires the result of collation every time the collating unit collates the write data and the data read from the transponder by the reading unit, word by word, performs radio communication with the one of the transponders, thereby writing the data to the one of the transponders when the collated data are not identical, and skipping the writing of the write data when the collated data are identical.

3. The radio communication apparatus according to claim 1 , further comprising a result-storage unit configured to store results of the collation performed word by word in the collating unit, wherein the control unit determines whether the writing of the write data should be skipped, for each word, in accordance with the results stored in the result-storage unit.

4. The radio communication apparatus according to claim 1 , further comprising a word-number setting memory configured to store word-numbers, wherein the collating unit collates the write data and the data read from the one of the transponders by the reading unit, in units of word-numbers stored in the word-number setting memory, and wherein the control unit determines whether the writing of the write data should be skipped in accordance with each word-number stored in the word-number setting memory.

5. A radio communication apparatus configured to read and write data from and to transponders, the radio communication apparatus comprising: a memory unit which stores identifications (IDs) to be rewritten to the transponders during a rewriting process; a reading unit which, in response to a write command instructing that write data should be written to one of the transponders, performs radio communication with the one of the transponders prior to the rewriting process, wherein the radio communication includes reading a first ID stored in the one of the transponders in a non-contact fashion; a collating unit which, prior to the rewriting process, collates the first ID with a second ID stored in the memory unit, wherein the collating unit compares a first group of words in the write data to respective words in the read data, and compares a second group of words in the write data to respective words in the read data; and a control unit, which performs radio communication with the one of the transponders in which the first ID should be rewritten including rewriting the first ID with the second ID when the collated IDs are not identical, and skipping the rewriting of the first ID when the collated IDs are identical, wherein the control unit skips writing the first group of words to the one of the transponders when the first group of words matches the respective words in the read data, writes the second group of words to the one of the transponders when the second group of words does not match the respective words in the read data, receives a response signal from the one of the transponders after writing the write data to the one of the transponders, and determines whether there is an error in the one of the transponders based on the response signal, wherein the write data is written to the one of the transponders, in units of words each consisting of a plurality of bytes, wherein the collating unit collates the first ID and the second ID, word by word, and wherein the control unit determines whether the rewriting of the first ID should be skipped, for each word.

6. The radio communication apparatus according to claim 5 , wherein the control unit acquires the result of collation every time the collating unit collates IDs, word by word.

7. The radio communication apparatus according to claim 5 , further comprising a result-storage unit configured to store results of the collation performed word by word in the collating unit, wherein the control unit determines whether the rewriting of the first ID should be skipped, for each word, in accordance with the results stored in the result-storage unit.

8. The radio communication apparatus according to claim 5 , further comprising a word-number setting memory configured to store word-numbers, wherein the collating unit collates the first ID and the second ID, in units of word-numbers stored in the word-number setting memory, and the control unit determines whether the rewriting of the first ID should be skipped in accordance with each word-number stored in the word-number setting memory.

9. The radio communication apparatus of claim 1 , wherein distances between the transponders and the reading unit are changing while the reading unit is reading the data stored in the one of the transponders and while the control unit is writing the write data to the one of the transponders.

10. The radio communication apparatus of claim 1 , wherein: each word of the data read from the transponders has a respective word in the write data; the collating unit determines word by word whether each of the words of the data read matches each of the words in the write data; and the control unit writes a word of the write data to the transponder when the word of the write data not matching a respective one of the words in the read data.

11. The radio communication apparatus of claim 1 , wherein the control unit: skips writing a first word of the write data to the one of the transponders when the first word matches a respective word in the read data; and writes a second word of the write data to the one of the transponders when the second words does not match a respective word in the read data.

12. A radio communication method of reading and writing data from and to transponders, the radio communication method comprising: storing in a memory unit data to be written to the transponders; performing, in response to a write command instructing that write data stored in the memory unit should be written to one of the transponders during a data-writing process, radio communication with the one of the transponders prior to the data-writing process, wherein the radio communication is performed via a reading unit and includes reading data stored in the one of the transponders in a non-contact fashion; collating, prior to the data-writing process, the data read from the one of the transponders by the reading unit with the write data via a collating unit; and wherein the collating comprises comparing a first group of words in the write data to respective words in the read data, comparing a second group of words in the write data to respective words in the read data, and collating the write data and the data read from the one of the transponders by the reading unit via the collating unit, word by word; performing radio communication with the one of the transponders to which the write data should be written via a control unit, thereby writing the write data to the one of the transponders when the collated data are not identical, and skipping the writing of the write data when the collated data are identical; determining whether the writing of the write data should be skipped for each word via the control unit; skipping writing the first group of words to the one of the transponders when the first group of words matches the respective words in the read data, writing the second group of words to the one of the transponders when the second group of words does not match the respective words in the read data, receiving a response signal by the control unit from the one of the transponders after writing the write data to the one of the transponders; and determining whether there is an error in the one of the transponders based on the response signal, wherein the write data is written to the one of the transponders, in units of words each consisting of a plurality of bytes.